From 5aac7c840b4a52a615acb1c0b64dbeda599c5a83 Mon Sep 17 00:00:00 2001
From: Simon Pasquier <spasquie@redhat.com>
Date: Mon, 9 Jul 2018 19:27:04 +0200
Subject: [PATCH] amtool: add support for stdin to check-config (#1431)

* amtool: add support for stdin to check-config

Signed-off-by: Simon Pasquier <spasquie@redhat.com>

* Address Stuart's comment

Signed-off-by: Simon Pasquier <spasquie@redhat.com>
---
 cli/check_config.go | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/cli/check_config.go b/cli/check_config.go
index 06047721..efaf7ebb 100644
--- a/cli/check_config.go
+++ b/cli/check_config.go
@@ -15,6 +15,7 @@ package cli
 
 import (
 	"fmt"
+	"os"
 
 	"github.com/prometheus/alertmanager/config"
 	"github.com/prometheus/alertmanager/template"
@@ -47,6 +48,14 @@ func (c *checkConfigCmd) checkConfig(ctx *kingpin.ParseContext) error {
 }
 
 func CheckConfig(args []string) error {
+	if len(args) == 0 {
+		stat, _ := os.Stdin.Stat()
+		if (stat.Mode() & os.ModeCharDevice) != 0 {
+			kingpin.Fatalf("Failed to read from standard input")
+		}
+		args = []string{os.Stdin.Name()}
+	}
+
 	failed := 0
 
 	for _, arg := range args {